Add URLs to depth tree from CSS

[dsgallups]

Hello! I have put some time into adding additional functionality regarding pulling from URLs in CSS (background image URLs and the like). This is necessary for my research project, and I am wondering if the maintainers of this repo would also be interested in seeing this implementation. My plan is to replace is_html() in downloader.rs with a struct called FileType. The scope of FileType is specific to this for now, and if you find value in my upcoming PR, a merge of FileType and ResponseData could be potentially beneficial in the future. Unfortunately, I'm a bit inexperienced with PRs, so I'll see tomorrow about getting into specifics. This is a fantastic library!

[dsgallups]

You know, I didn't take a look at the only open PR on this repo (#167 ). It seems like you are interested in this. I'll see what I can plow through tomorrow and attach! :)

[Skallwar]

This is a fantastic library!

Thanks for the kind words ❤️ . It's a hobby project for @CohenArthur and I. It's nice to see that people are using it and find it useful.

I might have some unpushed work on my laptop. Feel free to open your PR, reuse some of my previous work.

[Skallwar]

Related to #68 #142

[Skallwar]

I might have some unpushed work on my laptop

I lied :D

Feel free to work on this, I can assign you the issue (#68) if you want